my buddy recently got his 383 in his trans am. here are the specs lightly ported heads cusom cam 306ish promag sa rockers 30# injectors lt headers mad z28 tune.255 granattelli fuel pump

here are the problems

keeps geting a code 43 (knock sensor) we checked the sensor and it was fine.

fouls plugs like crazy

stutters really bad at high rpm and sometimes it loads up really bad at idle and will bareley run. seems like it has a miss

gets about 4 degrees of knock retard at idle but it usually drops off at high rpm.

car is very tempermental, sometimes it will run like a bat out of hell, (when it has new plugs) and sometimes it runs like crap.



any suggestions would help

 

What kind of A/F is it running?

 

i dont know the af we havent got it on a wide band yet

 

it also has a brand new opti so i dont think thats the problem

 

Get in touch with Ion and make sure there wasnt a mix up with pcms or the tune.

 

43 usually has to do with the circuit and not the sensor. Either the wire has no continuity or it is shorted to a voltage supply. When the PCM throws a 43, it will automatically retard spark. With the connector off the KS and key on, confirm 5 volts at the connector. If it's not, the circuit may be open or grounded. If ok, measure the resistance of the KS to ground with the wire off. It should measure 3300 to 4500 ohms. If it does not, the sensor may not be grounded at the engine properly or it is defective. Did he put the sensor in with some type of sealant? That could do it.

Your definitely running too fat. It would be best to eliminate the problem you know with the KS before trying to speculate about why it's running rich. Post back if you have trouble with the KS and we will help. The circuit is easy so it won't take much to figure out.

Dave